In Part 1 of this article we'll concentrate on the environmental factors that influence and help dictate which techniques and tactics you'll want to utilize while fly fishing in Jackson Hole. It sets the stage for Part 2 which will focus on specific techniques and strategies I've found useful over the years.
In brief, most fly fishing situations in and around Jackson Hole share three common characteristics:
In a nutshell, you've got the same type trout residing in similar habitat and influenced by similar environmental conditions. Is it any wonder a common theme is so evident and that what works on one stream will probably work on another as well.
Each species of trout share behavioral traits which help differentiate it from other species of trout. Browns are wary, rainbows jump and Snake River cutts are mean SOB's. They are very much a product of their environment. To survive they must be aggressive and opportunistic. As you will see, this has far reaching implications for the Jackson Hole fly fisher.
Another very endearing quality of the cutthroat trout is it's willingness to surface feed. Of all the species of trout, none is more likely to rise to the top of the water column for a meal than the cutthroat. When in cutthroat country you can almost always fish with dry flies if you choose. Other methods will certainly work too, and at times be even more effective, but if you are a dry fly die-hard you'll usually find enough action to keep you happy.
Freestone streams in Jackson Hole derive their water supply (primarily) from the snowmelt of the surrounding peaks. They support less vegetation and insect life than a typical spring creek and can exhibit widely divergent personalities at different times of the year. During run-off they are high, off-color and for all practical purposes, unfishable. This annual scouring does, in large measure, prevent vegetation from taking root as well as limiting insect numbers.
Later in the summer, especially in low water years, freestoners can be quite tame with a correspondingly significant reduction of trout holding lies.
Incidentally, Jackson Hole has many spring creeks. However, the vast majority of them are located on private property.
Various environmental conditions (including the habitat, as mentioned above) have significant influences on trout behavior:
Climate: Long harsh winters and a long run-off season combine to create a relatively short growing season for the cutthroat. Consequently, cutthroat trout must be more aggressive and opportunistic in their feeding patterns than trout living in more moderate climates. Factor in sparse Jackson Hole hatches and this becomes even more true.
Water Temperature Gradients: Here we are referring to daily fluctuations in water temperatures and how quickly, or slowly, they occur. Many fishermen, including the author, believe that steep temperature gradients trigger trout feeding behavior. In other words, gradients which warm (or cool) through a greater range of temperatures (say 50˚ - 62˚ as opposed to 55˚ - 62˚) will have a greater influence on feeding behavior during the time period in which the temperature change takes place.
In many parts of the country, the best fishing takes place during the cool mornings and evenings because midday temperatures get too warm. In Jackson Hole, the reverse is true. Mornings and evenings are often too cold with the best feeding activity taking place when the water warms in late morning and early afternoon. In either case, whether the water temperature is warming or cooling into the optimal feeding temperatures, the best fishing will take place during the transitional periods.
Typically, the best fishing of the day occurs at midday, between late morning and late afternoon. A normal summer day will see fishing activity pick up around 10:30 or 11:00 am and begin to slow down around 4 or 5 pm. If water temperatures warm too much during this time period you will often see a lull in feeding behavior around 2:30 or 3 pm, to be followed by an increase in feeding as the river begins to cool.
Keep in mind that I'm generalizing. Should the day be unusually warm, good fishing could easily extend into the evening, especially if a hatch is present.
Predators: In New Zealand, trout have no natural predators other than man. Huge browns can be spotted holding in open, crystal clear water. Such is not the case in Jackson Hole.
In Jackson Hole it seems as though everything that moves is trying to make the cutthroat it's next meal, or so the trout must think. Trout predators in Jackson Hole include, but are not limited to: herons, pelicans, larger trout, mink, eagles, osprey, otters, bears and man.
Needless to say, that's quite a list. Herons, pelicans and larger trout prey primarily on small trout. Mink, eagles and osprey focus on the medium size range while otters, bears and man can take on the largest trout with relative ease. If that weren't bad enough, huge lake trout in the 35 - 40 pound range have been known to attack and kill trout weighing 5 pounds or more.
With such a lengthy list of active predators, it's not hard to understand why you don't see cutthroats holding in open water. Snake River cutts had better hide or else! Cutthroats will use the following forms of structure to seek shelter: deeper pools and runs, rocks, undercut banks, riffles, and downed trees.
Riffles provide so-so cover at best. Abundant food and oxygen will lure trout into the relative openness of riffles. But since the surface of the water is broken, trout are hard to spot and relatively safe from aerial attack. None of this, however, will stop an otter or a mink.
If you've spent any time fly fishing in Jackson Hole you've probably noticed that the preferred lie for large cutthroats are deeper pools alongside fallen trees. If you think about it, it makes sense. Overhanging branches prevent aerial assaults while submerged branches provide a handy obstacle course within which trout can maneuver to escape mink and otters. Those same branches are also great for snapping fly fishermen's tippets.
Sparse Hatches: Don't get me wrong here. I'm not saying that Jackson Hole does not have good hatches. What I am saying is that most of the time hatches are limited rather than profuse. In many ways, this is a boon to the fly fisher and a big part of what makes Jackson Hole fly fishing so attractive to beginners.
The scenario runs something like this: the occasional insect hatches and begins to drift downstream. Lurking cutthroats, which don't have the luxury of passing up potential food, immediately attack because they don't want to miss a feeding opportunity nor do they want to be beaten to the food by another trout.
Compare this to a typical Henry's Fork scenario: a profuse hatch of #18 Blue Wing Olives carpet the water. Food is abundant so there is no competition from other trout nor is there the imperative to eat every bug that moves down the river. Casts must be deadly accurate, drift perfectly and be synchronized with the feeding rhythm of the trout. Sound tough? Rest assured, it is.
Food Sources: Without getting into every hatch that you might run into in Jackson Hole I'd rather point out some of the important characteristics of the food supply in general. Some of this is unique to our area and some of it is simply contrary to what many fly fishers have been lead to believe.
While Jackson Hole may have sparse hatches, what we do have is a wide variety of different food types. It amounts to having a few specimens of lots of different food types floating downstream at any given time.
Of course we have the usual assortment of mayflies, caddis, stoneflies and midges. But the list goes on: grasshoppers, crickets, beetles, ants, spiders, craneflies, dragonflies, damselflies, leeches, sculpin and other small baitfish, moths and just about anything else trout can get their greedy lips around.
What almost everything on the above list has in common, and what is contrary to much fly fishing dogma is this...rather than simply drifting passively downstream, they tend to be on the move. That movement could be a small twitch, big leg kicks, fluttering wings, writhing cripples, drowning, skating or skittering, or even sprinting on the waters surface.
Many anglers have become convinced that the only way to catch trout on a dry fly is with a dead drift. While the dead drift is often quite effective in Jackson Hole as well, maintaining strict adherence to this technique will drastically reduce your opportunities.
Now that you have a better understanding of how the environment influences cutthroat behavior it's time to apply that knowledge to your fishing. Building on the information presented in Part One, Part Two will discuss specific dry fly, nymph and streamer fishing techniques and tactics and when to use them.